SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ff786b6e91ccd818a9863e30d00ba2914ebb2782832e7eeed45704c5e88ffa5' 
  AND token = 'w0KW7qp8MOZ43m0Jw9+o15zhqzUbGVdHnXkYi4mgeSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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