SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3aee16bef45bdd02576f64fc0870a6f1f39e8a60cf12284bc3d979ce6660434' 
  AND token = '+IosqTObEydJrEsfhr4aKGe+ZY5W87IOYBwsmAw6RBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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