SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e5aea84f9ee269580ecc6e8ca6bf9b1337bce57ef58b2f9e23318e2acd6c1c1' 
  AND token = 'uZM5dVQPQvcxj/DnEBNMeaKwzuU4b2sfiwBxfY0TlBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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