SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f93c95884324b6020e441b528e8dc9307882604900b33ddaa00819745a1541c' 
  AND token = 'PxYVRDaqZZKycQcn39tEIA6aHycr2hxZ/OC8DDqq8mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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