SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c62183192bc58e0d9bf689d290f3f199f042865bf4c1d2074773565bf7d51b1f' 
  AND token = 'VqCCJN7dwAXjmM5k1lYL6+EOAgt6/MyXxXfYoKSAm3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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