SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d4ba9166f577442238235151e5f319d28aeb82070a0b6e89db99fc63f8abc2d' 
  AND token = 'j/smJVk8pqiVM+ApC5VeDGWrJC5bQPVKtag34Z4VbNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}