SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a5af124a56edb5fe4e45c931116d438a352076219519bfa6e067d6f145f99cd' 
  AND token = 'A39vKrnzHID8cUesI/CNndW9AsXS6I53NWxRAzv8zFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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