SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bffc13b86a3c8cec277c8f1096dec0e75b219f9af7d4ad1adc0735373c496a1' 
  AND token = '2gTuWdrdfFoELqvtKx34w0/g3gCIQgS2lBZ4/vdiolw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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