SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9253b5a6072d1c7943c4758abee5c14ebc82ad8f7230d421f2f574a2beaac52' 
  AND token = 'jRjZNWwQTBIjhcUf/3HkTwRB+CRw0ytxwdWzYmP2Rcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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