SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c615746ea7eb4e53a218dbe1874cb155fcbc452385628c29759e676c1794cd4' 
  AND token = 'vvg9m9MYzuEhTue4SSiTYB8yKvFo5tr0/mvVH8H6D7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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