SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2fbd6e7c888a9b54b0f76a9dd7508cd864146f660c945ca7d88676d2a066bef' 
  AND token = 'KyVaMFX3uxJbgpfwMseAG8VFKXSTsanM+UVAxUBp58Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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