SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c33842d79e27369612620a505ca971aa4811aeb031bfd38ebb2b0fd13e8d00c9' 
  AND token = 'JEMHPPeRGJUOrSvhX8w28xearkFF4yCVJAC2FIAwy5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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