SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1dd50bdab67d66ae1360589be031ae7600d9becfe725ad82dca74422d62d05f' 
  AND token = 'j9/Cgu6Iq16wWPuRllaEV+5ZKGJs2SraadrnyccNxpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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