SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ae6cef78965ba089b4853175f5cc3cc12db9040b4e4e818d658617b9a517f76' 
  AND token = 'GEmgk0GYBj00uBREGBRnHCvwWgqcE6XZtP2u8JtdPzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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