SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3b1518ebc39bda5e2be79ca69739c21c2320f197ab899152194a8eb1fee042a' 
  AND token = 'auJoNAklzTwBEdXExOPSQaAxwYinSAg1hTLLFHzrfac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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