SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85e3176aa2ee96a85c7cb9639c0e20895445907369a750041df8e73a863a6171' 
  AND token = 'e68spimUB8jAx2iB33G0Z3mM8lWavjLvTVbd3uyyDXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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