SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24f44d2787298cb947a0b6268ecd06ef3d27c30b7beb14d2835beb79d5918896' 
  AND token = 'Zr4vmDzDvCJEpHoLj7kCLTZ4ELZoD8UbuOjyjbYsnAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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