SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee59d66b16392c064942cf6577d92142524ff40da802ddb3d4db8a28aca3966e' 
  AND token = 'k+NjX0YX1CzFBQDqJFuqlWLPNQC5vptOxewrFVHjatk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}