SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fc3acd6c0ff337df37fa7e9cc4fb6a00145b2eb6df51145beb3b4c1837619a9' 
  AND token = 'aWaHL/qZIJuh2qe3oszWFaIlhGcxXfLMZ+b3XJjqp/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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