SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74c38f1a208866f3bf73ec9fecebd853461127ae963a58632083bce6b9a841d1' 
  AND token = 'kdNTET5cEYAjyRRzgwFlBCCIXk4I+1OkDBIEa1woo+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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