SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cfae963aabc51ea1f05acacfd33936cc223269f00120cacba93036e4f2b89c5' 
  AND token = '5rUo/dgRWZ7uJjv6zlffw/MFEMImBU83v5YjZzHbz5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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