SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '756a6b5b870d2733dbd95712661ac66b940fa0662ff08e0c60fcb77412fac212' 
  AND token = 'wlzsejrVmzxubRhOSXxFMJq5zGq2zSn9nkiosyOAKgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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