SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85d1a8d1609eac968f313d861a0f5b6028cea016e7ef43251fa087a843b065b2' 
  AND token = 'VvOQNXCKTwxVr0hR3qwqt8j9RF9YMaoUuSG29Alw//c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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