SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb82b9fccf88d53bef93deb87d90c65597925f025c0c6eff62dd681c14204017' 
  AND token = 'C35DY1pNIeTiGQEcFLqByDl/z0Ra4Hoon6bzUT0wSE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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