SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '449d721751c676bc4755ebdbe73df49cb965778a3d93f36ad039e9f9595b6741' 
  AND token = 'reA8fcl4c9qEk0qGeznSoibEEtoVulAoCKhQ8irjDiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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