SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa35a66c59512048e042eb0d5dcc8773547f8a8d608eb41b3f984cbe7042f5e5' 
  AND token = 'Rw7dL+0KLq9dqw0aM8ejeIySh46aBtJepnM68qWS0b8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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