SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90479e9cdade1732ad0ca3efc362b41eedcfbe005e187df207d461a3f13c5e0e' 
  AND token = 'UDeSGmjwpuHqom9teY7Wvs5xT+bhOcQVmupjuUPDhiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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