SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc91c4373e040d4df51ea1674b50f2ae5674677b2f184fbdf94c439d5a2e1ae5' 
  AND token = 'Jc0fbv7tVYWKY8gUuVBShVgXKPzwlCfvevdafWx+9PA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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