SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44bce95549536140347221db3687aeccf86b58be91c63ee5344425ae674b857f' 
  AND token = 'Me7xJhVsfNVVfS1TT4RoANhXMOcgBAuak17wGm2jGBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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