SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb2576150954a99fbfbc16ab5099f00357957017f456b531b601690290ac6524' 
  AND token = 'NMWLomjsSXYrOxLgMMtsSSWk00gqY1TR5elif9Ryqis=' 
  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"
    }
  }
}