SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfb00e1dfbe3061ef7d1ca3d9f9a01ffd7b6d94e01565e6f0eb0f8abab1d4e3c' 
  AND token = 'aJoVQsWGI4zXjfU1FL7Xlhe96B5aKHIKHH0m7MlOpQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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