SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c45031749c5273ed8bc24d7ca783fac7581af24b288c65b6737cab7731fbc62b' 
  AND token = 'h5CkaCVVmWK6FLuFg9Icmx2BBnNKlp1Yt2GpyxQ/wk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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