SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a7b6fdbd5035e35f1f3b80b8a2031318a53a863f3973c6e5f80ddfd92c1b58b' 
  AND token = 'uK0U761U1npu171WK+L6Snt5jNTZT2Q75EFITw3Xn3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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