SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a42f750eab5a90e6853fa54aa47d05cc32dbefe30030baa6f013b22510f5c84' 
  AND token = 'WDkkpdVLWe/37/ILwsyqLJJE07KWBtyT9G0Gs31RmK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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