SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a7feadd28c4b1b1e7ee25aab3dd5824979b63f5057c3733e84e32387d1e9ef6' 
  AND token = 'P70BCjnhTZIabHzSKiYNV9LsLjXas3WVNwF/sz0Er5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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