SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe1df27b4ff96fee7f132e2eec2fc9b15cfcd482a9ab088681499de9c6619672' 
  AND token = 'WE43hVc7Ltq/sTQKINgHIIrQVVLILCfZlfcgiy/swns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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