SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0294756d788aa96bf14b5b1c54d04f77cc46f0ff03913c39e1a2b38c64188be3' 
  AND token = 'Agk8KItPukThn1FUCax1r9qJpFOeBKnQJOOVwCEnvg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}