SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfcf639e7d5fb55fbd3a0ea47ace1522109e67735148ab998940aa215ebed325' 
  AND token = 'xqd3ihIveQwWPh/hP/P2T6jYntMmCs+vUrskRfO3Jn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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