SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfbff4e9b75d97aa240cbe7157134c2b7b23df12297cfb5156c5a80321552416' 
  AND token = 'EnLUWYnxMZWhqWGswitRv3wQH3G0hCSuatEBuEAq2VE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}