SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cd56c7191296be6aee6ae88fcb4ae0c55e365e00367fd7c18dd205796cbb9631' 
  AND token = 't/6bLh5QP5FDdM1CGzGIqoFD/eb4kakgQ7Ulmjs9fvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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