SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a242d23e1678faa769c10c2c9be93791d448e3c3ce328c4518ff181b4aa8086' 
  AND token = 'fdammOHOJ9fB4x1jf2HeIJN6ors/5iVWneEXVqEoX7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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