SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '913e648c66f53ea770ebd67c69b67e79f9fd96cf74f6529c0d414f22ab10cb29' 
  AND token = '51htLbwEMAu2tonr0jvAGSqtiQ8v3ZoJC2huMHhpXdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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