SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '286b5f87db53619027c45766b63744967b09f638d9271c98b18dc45e424e4c7b' 
  AND token = 'C818so5D4Dg87E46/mpbBd5cWO+Aj71cen1R4c2OSes=' 
  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"
    }
  }
}