SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3285d7cec644c38bf8c6c0702a58b68176a00b32108ace431a65380c9776ce8d' 
  AND token = 'VpELVawY5ISC9F+qTtQf/KdxbezQ4FcKjyqS0OCDNZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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