SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '283a807e75d33f63d421f1ec95d884dba8cba72852473bc43b16e55def2c91ad' 
  AND token = 'ypElZpzeZINC5HtsO4InEfzhKM6eCKqgymAVHI9JmkQ=' 
  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"
    }
  }
}