SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a387469a622a64e85de110ab55ff85536d0993f8a17a8d426f3134a0bfd3cfe' 
  AND token = 'ZJnB2Cv56wgxKpXPWNQGoa7Lh9oN1OAwUFUQucwiJ1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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