SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b72fa140605f6aca5166d7ba00ed611d7c5d081f1c9365c4565bd32274e3b36d' 
  AND token = 'zuDv/O3XPohP20UjGZdbaAfq1vJvtOQqL/vCPiZAJVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}