SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a378691bdebcc6dafa89db311ea62e5e52886d4390fc199e1326c98ba0fa9095' 
  AND token = 'gcwdl0knq6kcsQ4Y1/18rd5oBCyEDhkGwMShcS44KNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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