SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21c1c24edb8be7c3f9a2081672bc65faabda13b2ee473c71a53343b9c1464a12' 
  AND token = 'B/ery8dCB/jZ5GP/rwhV0KXsXumDmB+iDy+HpsDuCqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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