SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f050819ad42f459d28c96b9bdad1911d185ade46412062913ac207d7bdc584c8' 
  AND token = 'OyFzotvQf1LtPBnnmqrwe+P55VRicpTAWA4RtXN+2WU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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