SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1868fa2fb383aa686484a2edd159535dc4fe644f2b85217d654eff7f701d39ab' 
  AND token = 'YAXfGADHceUI+HLjcYasGvLLeXwH96Oc7j8fdShp930=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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