SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd9627738c437e4758aa69ca1dc4c6ced7eb762aaf5a1b6461131f37181245ad' 
  AND token = 'SFlXYJDURPSE+GitBOW74rzwVEMvPRQHvxhQI8B5+Oc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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