SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62539190c95e1387454948bd7632852179bc1f3c484f2348733c2a4bff010677' 
  AND token = 'zQ+QpaYtSgeQ1wxAG243ZHKYjXXgYe96JGKzqEZ6nCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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