SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67e9ef21a8746a8991302fb0851ca7f826cdec60336ca297ab439e436d3768d4' 
  AND token = 'iGL3Im8MTojJVwiECYZdZxKs0BGDjirA6qQJnD+1xQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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