SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62c502d82ea86f95177ea401c6b860bcedc969257ba24609451f2fcee84ce567' 
  AND token = 'ZyfhhnLD4F/xyG7ZZ4PEybC6Ip3aSmvzFOdU2AQqzKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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