SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfa97d27ff08177b8adbbb20fb2b065da34514a136d5ef734e8b2b64ace64cf7' 
  AND token = 'mQcO8IqpRoFNhyT1FApEoDklLmDxgQpWAILxadGTPLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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