SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '110ff0c11255f5eb545ff077563464352a80d3936d7fcaaba411bcb418f698d6' 
  AND token = 'AJUIuYaIYD+31tyyV9dhTQUeIWROc/B7IFPNooydoMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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