SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd6ace0c180bf9b25d20f0fd479f4388568e875303a9baf99eac0f3be294575a' 
  AND token = '9SyFM1qfdzxeSt6nagFIbre9H0aPVdoDMa2pMOio4PE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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