SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89573025c2e471860c5271e2504531bcce4436be918cb736e3d25b9aacec4f7c' 
  AND token = 'drpuor4dVf7DhE3h7ufwfri8ko9N4AgCClNIq4VReyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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