SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '950a3ed323491398aa09782e629fac0124eb8bd58dc213e49f391965869006c2' 
  AND token = 'sF4KjwTJgsRX5vg4tlegwnsKlsAmmdHFA2hWqslBPuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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