SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5641ead4785fdd5f5c02c686fcfaee18457c7c9efeb2662f4fb6580987f93d78' 
  AND token = 'h05PbWE6ay0lTCbHIOeSXllGEAQ0sbgFRcql7kjTrgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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