SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77b29cddf14f8fe31b3dcb1e8aeb4491bd2c8320c82bb85b9a8469d996b31cf9' 
  AND token = 'gp4vwcW4lFa4Y0Rz8zP+Ur92ewlzWPfshtl8hiEfH0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}