SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6228f37129ce67eff2047f4f1de1d039e2d0c61355e39ed7b19a406004727750' 
  AND token = '3X+XGAayLfkmH14fANMVAGhfsF1boQxvAbDx7XR88rc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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