SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2145d39afa9abff2ee4c0eaec2e9f7df8e96183b60016dcbe8f158cdf560f59b' 
  AND token = 'rFEQJnn3hZa0LfCdhbW4XKxzQeZPZfMo219T1BlRFPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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